Towing system.



No. 891,352. PATENTED JUNE 23, 1908.

W. L. MERRILL.

TOWING SYSTEM; APPLIOATION FILED rnB. 9,1907.

W/T/VEISSLKS.

09 Q I WMBUR L/V/ER'R/LL My inventionrelates to towingisystems,

and is particularly applicable to the control of electric wincl'iestor towing barges. Asatisfactory system for towing should embodythe following features hen the speed "of tl'iegvessel1s nicreased, the hawseli should be lengthened to avoidsudden'shock,

" and then should be gradually; wound into reducethe distance between the two boatstto the original,amount. --If the. forward boat should be slowed down, the, hawsershould he reeled in to take up the. slack, and then grad-- ually' reeled-out to maintain the. proper distance between the two boats Myinvention consists in so. arranging the.

control of the hawser that the illis-in.-v creased when the distance between the ships increases, and is decreased as the distance between the shipsdecreases. I accomplish this by providing yielding means for. paying out the hawser, and-meansior automatically increasing the pull on the hawser with the "amount paid out.-- More-specifically stated, I provide an electric-motor-controlling the winch or windingdrum, and means con: trolled the movement -:of the winch for controlling the'tor ue of the motor.

My invention'will best be understood wiiieni Figur 1 reference to the accompanying drawings, in

s'hows' a tug and its tow; and.

of-thefcontrolsystem. 1 Y i In Fig. 1, A'repre'sents the tug and A -t-he 2 shows diagrammatically the arrangement I tow n tedty the haws'er- B'; This haw;-

ser is made fast to the tow; and at the tug is controlled by means-of the apparatus shown diagrammatically--in*Fig: 2: In this figure C represents a winch or. drum forpaying out the hawser. D represents an electric motor geared to the drum and controlling the pull' on the hawser. The field (Z of the motor may be series, shunt, compound, or separatelyexcited. In the drawing .1 have shown it separately excited from the constant potential circuit E. F represents the armature of an electric generator supplying current to Sunni-1' orscuiaxico'inni', new roan coin-Liana oonronivrlox'or;Newroan.

Specification of Leaas aaitgig BEST AVAILABLE COPY "icxon ro cm unit]; icLecr iioi I Patentedi ifu rie 5 t, V g I applicat on filed February 9, 1907. Serial No. 356.557.

the motor armature, if represents the gen erator' field, which is connectedacross the constant potential circuit E through a resistan'ce G. Resistance G' is provided with a short-circuitiiig de ic'e II, comprising two magnet windings, of which-one, h, is placed in se'ries with the mot-or a rn'iature, while'thc otlier', "'l", is connectedacross the-constant potential circuit E through the variable resistances I and J The resistance J is employed i nerely for the initial adjustment of the system, while the amount resistance I in circuit is" controlled automaticallyby a contact carried by a nut K, which is InQVCd by a screw i'ornied by an extension of the shaft of the drum I r The two windings hand it assist each other intending to open f the short-circuit around the resistance (3.. If the current tl roughthe itlntlil l" h were constant, the winding 7; would tend to maintain a constant torqueon the m'ot'orD, since if the motor currentjand consequently the motor torque, should rise above. a certain. amount, the increased current iii the winding h would remore 20 the shortrcircuit from the resistance G thereby decreasing the generator voltage an d consequently the motor torque; while, as soon as the, mbtorcurierit fell below ajcertain limit, magnet winding It would be weakened sufli- '85 ciently to allow the. contact memberI-I to short-circuit resistance G again, and consequently again to increase the generator voltage. This tendency toward maintaining a constant-torque on the motor is modified by the action; ot magnet winding 71-. The strength of this Winding. is controlled by the amount-of the hawser thatis paid out,-or, in other words, by tlieposition oithe drum C, since, the position of this drumfdetermines the position of the nut K, and, consequently, theiarnount oi resistance I which is in c ircu1t. For instance, ifthe two' lv essels are moving underinormal conditions, fan'd the forward vessel-suddenly; speeds up due toany cause, the increased strain on the liawse'r B will cause .it to he; paid, out,- thereby shifting 'the nut-K away from the drum C, and increasing, the amount of resistance I included in circuit with magnet windin h. This'magnet winding 71/ is consequently weakened, so that the. current in magnet winding it must rise to a greater amount than before, in order to remove the short-circuit from resistance G. In

other words, the torque of motor is increased bythe aying out of thehawser, so

tween vessels. It the forward vessel should slow down. suddenly, the hawser would immediat-ely be wound in by the motor D, but

this would move the nut K so as tocuta 3 portion of resistance I out of circuit and strengthen magnet winding h. The current needed in magnet winding 71 to remove the short-circuit from resistance G would consei quently be decreased, thereby decreasing the torque of the motor D, so as to allow the hawser to be paid out again, and to restore F the distance between the vessels to its normal amount. I

It will be understood that I have illustrated my invention diagrammatically, and

consequently I- do not desire to limit myself to the articular construction and arrange ment 0 parts here shown, but aim in the appended clairns to cover "all modifications which are within the scope of my invention.

IVhat I claim as new and desire to secure by Letters Patent of the United States, is,

1. In a towin system, in combination with a hawser, yie ding means for paying out said hawser comprising a drum and an leo trio motor geared to said drum, ,andmeans for automatically inc'reasirn the pull on said hawser exerted by said. yieIding means with increase of the amount of hawser paid out.

2. In a towing system, in combination with the hawser, a rotatable drum for paying out said hawser, an electric motor for producing atorque on said drum, and means controllable by the movement of said drum for controlling the torque of said motor.

3. In a towing system, in combination with the hawser, a rotatable drum for paying out said hawser, an electric motor for producing a tor ue on said drum, a screw and nut operat-dil by said drum, and means controlled said screw and nut for con- 4. In a towing system, in combination with the hawser, meansfor paying out said trolling the'torque of said motor.

hawser, an electric motor controlling the pull j on said hawser, and means controlled by variation in the eifective len th of said hawser for controlling the torque 0? said motor;

5. In a towing system, in -combination with the hawser, a rotatable drum for paying out said hawser, an. electric motor geared to said drum, and means controlled by themovement of said drum for varying the torque of saidmotor. p I

v(5. In a towing system, in combination BEST AVAILABLE COPY controlling the voltage of the generator.

8. In a towing system, in combination with the hawser, a rotatable drum for paying out the hawser, an electric motor, geared to g the drum, a generator for supplying said motor, and means controlled .by the movei ment of said drum for controlling the voltage j of the generator.

9. In a towing system, in combination with the hawser, means for paying out said i hawser, anelectric motor controlling the pull on the hawser, and atorque-controllingdevice for said motor comprising two magnet windings. one controlled by variation of current in the motor and the other by Variation in the effective length of the hawser.

10. In a towing system, a combination with the hawser, 'a' rotatable drum for paying out the hawser, an electric motor geared to the drum, and a torque-controlling device for said motor comprising two magnet windings, one controlled by-the'cnrrcnt in the motor and the other by'thc movement of the drum. I 11 In a towing system, in combination with the hawser, means for paying out said hawser, an electric motor controlling the pllll on the hawser, a: generator for supplying the motor, and a voltage-coxitrolling device for the generator comprising two magnet windings, one controlled by variation of current in the motor and the other by variation in the effective length of the hawseri" 12. In a towing system, in combination 'with the hawser, a. rotatable drum for paying out the hawser, an electric motor geared to the drum. a generator for supplying the motor, and a yoltage-cont'rolling device for the generator comprising two magnetwind- I ings, one controlled by the motor current and i the other by the movement of the drum.

In witness whereof. I lnivc hereunto set my hand this 7th dav of lfl-liruarv. 1907.

tion in theeflective lengtlrof said hawser, for 7 

